A promoter is a nucleotide sequence to which RNA polymerase binds so that gene transcription may be initiated. See generally U. Goodenough, Genetics, 267-70 (3d ed. 1984). A promoter may consist of a number of different regulatory elements which affect a structural gene operationally associated with the promoter in different ways. For example, a regulatory element might enhance or repress expression of an associated structural gene, subject that gene to developmental regulation, or contribute to the tissue-specific regulation of that gene. Because appropriate modifications to promoters can make possible optimal patterns of gene expression in recombinant DNA procedures, see, e.g., R. Old and S. Primrose, Principles of Gene Manipulation, 138-140 (3d ed. 1985), there is a continued need for new promoters having modified functional properties.
A putative cardiac troponin T gene promoter was preliminarily discussed in Cooper, T. A. and Ordahl, C. P., J. Biol. Chem. 260, 11140, 11144, 11145 FIG. 6 (1985). This work did not teach the upstream boundary of this promoter, did not disclose the different regulatory elements of which this promoter is comprised, and did not teach how this promoter could be modified (through an understanding of its regulatory elements) to provide new, modified promoters with features different from those of the native promoter. The present invention is based on continued research into the structure of the troponin T gene promoter.